Trying to keep this concise and sort of lighthearted as it's weirding me out. 
DH friend Dave was/is married to Janet. He met up with Dave for gigs etc as they have a shared music interest. Janet also went to gigs with them as did her best friend, Sally. I met Janet and Sally quite a few times and all very friendly.
Six months ago Dave and Janet suddenly split up due to his excessive drinking, apparently. He's now sober and came around last night, and introduced Sally as his girlfriend! We had a pleasant enough evening but I just wanted to ask 'where is Janet? Are you still friends with her Sally? Was this an affair? Does she know?
I know it's none of my business and DH doesn't know anything but it's like Janet never existed and that her and Sally were never bestfriends. Sally was talking away quite happily about their plans and future and they're moving in together, but no mention of Janet.
It's makes me want to shout JANET and see if she metaphorically appears.
She did exist as I met her!
Am I losing it? Is this weird? Should I ask? 